[T10] [SAS] Clarification on how to handle "Enable APTA request" from Link Layer to Phy layer

Tim.Symons at microchip.com Tim.Symons at microchip.com
Thu May 16 16:34:33 PDT 2019


Lana,

When there is no connection pending or established SL_CC0:Idle state transitions is a steady state and there are no events that cause this state to be re-entered from itself. It is intended that APTA is only available to operate when a link is idle, the Enable APTA request to the Phy layer to enable APTA is only required to be sent once.

If a connection is pending or established then APTA events are required to cease. It is correct that PAPTA_A_L0_IDLE to PAPTA_A_L1_WAIT_FOR_START state transition happens only time before SL_CC0 to SL_CCn state transition (n= any valid state as per spec).


Regards
Tim.


Tim Symons | Storage Architect
Microchip Technology Inc.
Tim.Symons at microchip.com<mailto:Tim.Symons at microchip.com>

[Microsemi_Subsidiary_Logo_4C_BLK (003)]

Regards
Tim.


From: t10-bounces at t10.org <t10-bounces at t10.org> On Behalf Of Lana Chan
Sent: Wednesday, May 15, 2019 4:04 PM
To: t10 at t10.org
Cc: Kazuhisa Murayama <murayama at cadence.com>; Gurudatta Mewundi <gmewundi at cadence.com>; Deep Mehta <deep at cadence.com>
Subject: [T10] [SAS] Clarification on how to handle "Enable APTA request" from Link Layer to Phy layer


External E-Mail


Hello SAS Experts
Can you please help clarify "Enable APTA request" handling from the link layer to the Phy layer:

Specification reference(SPLv13):
==========================
1)      As per section 6.18.4.2 SL_CC0:Idle state and 6.18.4.2.1 State description


This state is the initial state and is the state that is used while there is no connection pending or established.

Upon entry into this state, this state shall:
h) send an Enable APTA request to the phy layer.



2)      As per section 3.7.2 Transitions

Upon entry into a state, all actions to be processed in that state are processed. If a state is re-entered from itself, then all actions to be processed in the state are processed again.



Question :
========

  1.  Is the Link layer required to send "an Enable APTA request to the phy layer" at every clock/time (continuously) where it is still there in SL_CC0 state in case of No connection request (if it is considered to re-entered from itself)

OR


  1.  Is Link layer required to send "an Enable APTA request to the phy layer" only at one time as it is entered in SL_CC0 state ?
     *   If this is the case, then PAPTA_A_L0_IDLE to PAPTA_A_L1_WAIT_FOR_START state transition happens only time before SL_CC0 to SL_CCn state transition (n= any valid state as per spec)
     *   As this state transition has indirect dependency on "Enable APTA request" from Link layer.

Please let us know your thought on this.

Kind Regards
Lana



-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.t10.org/pipermail/t10/attachments/20190516/b1c2cd70/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 5419 bytes
Desc: image003.jpg
URL: <http://www.t10.org/pipermail/t10/attachments/20190516/b1c2cd70/attachment.jpg>


More information about the T10 mailing list